Liner Hanger Setting Tool and Method Enabling Traditional Bottom Up Cementing or Tack and Squeeze Top Down Cementing in a Single Trip

ABSTRACT

A liner hanger is initially set to the surrounding tubular. A standard bottom up cement job through a shoe at the liner bottom can be performed. If that job does not test satisfactory then the running tool can be unlatched at the packoff and raised beyond the liner hanger extension tubular so that a tack and squeeze job can be accomplished pumping the cement top down through the gaps in the liner anchor. The running tool can be re-latched to the liner hanger extension tube that is still unexpanded. Once re-locked into a groove in the extension the running tool for the liner hanger can be operated to set the seal and release the running tool from the groove in the extension to pull out of the hole. The liner hanger anchor and seal can be expanded into the set position by the running tool.

FIELD OF THE INVENTION

The field of the invention is hanging and cementing liners and more particularly a setting tool latch that can release and re-latch to allow one trip functionality to perform a tack and squeeze job with a standard bottom up cement job and setting the liner hanger seal thereafter.

BACKGROUND OF THE INVENTION

Liner hanging and cementing typically involves putting a liner and a liner hanger in position in a borehole with a running string. The anchor portion of the liner hanger is set either by applied pressure on a dropped ball or by expansion of a slip cage with a swage driven by a combination anchor and telescoping member that moves the swage. When the slips are set and the liner is supported from the surrounding tubular, the cement can be pumped though the liner to the lower end where there is a cement shoe. The cement goes through the cement shoe and into the annular space while displacing well fluid ahead of the cement. The well fluid is displaced by the cement through the open spaces between the set anchor in the liner hanger. After the cement is placed the anchor and stroker for the swage in the running tool is engaged to expand the seal in the liner hanger. Alternatively the seal of the liner hanger can be set with internal pressure on a piston assembly, usually done after another ball is landed on the seat inside the liner hanger or another method such as a flapper to create an internal pressure on piston assembly. After the liner hanger seal is set the lock for the running tool into the liner is released and the running tool is removed.

In some unconsolidated formation the traditional bottom up cementing through a shoe may create an unsatisfactory cement job as large voids may concentrate the cement in a single area as opposed to sealing the liner along it length as envisioned. In the past the next step would be to pull out the running tool and run in again with an assembly to set the seal after delivery of cement above the liner hanger and through the gaps in the anchor portion of the liner hanger. Thereafter the hanger seal would need to be set. The extra trip to do a tack and squeeze job was necessitated by the limitations of the existing equipment designed to release the running tool for the liner hanger only after the liner hanger seal was set. In order to do a tack and squeeze job with the known expandable liner hanger such as TORX® available from Baker Hughes Incorporated of Houston, Tex. USA the liner hanger would need to be retagged after release and raising above from an extension pipe associated with the liner hanger that is not expanded. This meant that the locking dogs would need to release to allow the running tool to be raised to do the tack and squeeze job and then the running tool dogs would need to enter an unexpanded portion of the extension pipe to re-latch a groove in the extension pipe so that the anchor and stroker can further advance a running tool swage to expand the hanger seal. This component with the locking dogs known as an RS packoff in the TORX® product family, was not designed to do anything but release one time after the packer seal was expanded. In trying to do a tack and squeeze job with the TORX® liner hanger the problem after the initial release of the RS tool would be that the dogs would stick on the taper between the expanded going into the unexpanded portions of the liner hanger extension pipe and the running tool would not be able to re-engage the liner hanger to allow use of the anchor and stroker to finish the expansion of the liner hanger seal.

The known RS packoff seal is discussed in U.S. Pat. No. 8,132,619 with the dogs being 204 that are released from a groove 202 in the unexpanded portion of the liner as the mandrel is raised after the liner hanger anchor and packer are set. This design for the packoff seal was not amenable to release before the packer seal was set followed by a subsequent re-latching. As explained above the dogs would jam trying to re-enter a decreasing taper to re-extend into groove 202. This reference is fully incorporated herein as if actually set forth.

As a result the old design for the packoff 194 in U.S. Pat. No. 8,132,619 has been reconfigured to allow release after extending the liner hanger slips so that a tack and squeeze job can be undertaken without a trip out of the hole and then the packoff can reengage the groove in the unexpanded portion of the liner hanger extension tube so that the anchor and stroker of the running tool will be anchored to the liner as the liner hanger seal is expanded after the tack and squeeze job. In essence the present invention by providing the improved packoff latching assembly with new functionality of release and re-latching enables a method of running in a liner hanger and setting the anchor portion of the liner hanger followed by the option of doing a standard bottom up cement job and if that is not satisfactory doing a tack and squeeze job without having to pull out of the hole. In essence a standard cement job and a tack and squeeze job can be performed with a liner hanger in a single trip. In the preferred embodiment the liner hanger is set with swage expansion but the present invention contemplates other styles of liner hanger in a one trip dual cementing functionality method that still allows the liner hanger seal to be set after the final cementing operation. These and other aspects of the present invention will be more readily understood from a review of the description of the preferred embodiment and the associated drawings while appreciating that the full scope of the invention is to be determined from the appended claims.

SUMMARY OF THE INVENTION

A liner hanger is initially set to the surrounding tubular. A standard bottom up cement job through a shoe at the liner bottom can be performed. If that job does not test satisfactory then the running tool can be unlatched at the packoff and raised beyond the liner hanger extension tubular so that a tack and squeeze job can be accomplished pumping the cement top down through the gaps in the liner anchor. The running tool can be re-latched to the liner hanger extension tube that is still unexpanded. Once re-locked into a groove in the extension the running tool for the liner hanger can be operated to set the seal and release the running tool from the groove in the extension to pull out of the hole. The liner hanger anchor and seal can be expanded into the set position by the running tool.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is section view of the packoff between the running tool and the liner hanger extension locked after the anchor of the liner hanger has been set by expansion;

FIG. 2 is the view of FIG. 1 showing a mandrel latch engaged after some upward mandrel movement;

FIG. 2A is a section view along line D-D of FIG. 2;

FIG. 2B is a perspective view showing the flow passages seen in FIG. 2A;

FIG. 3 is the view of FIG. 2 with the dogs unsupported in the surrounding groove;

FIG. 4 is the view of FIG. 3 showing further mandrel movement and the flow path of cement for a tack and squeeze job after the mandrel is lifted above the liner hanger;

FIG. 5 is the view of FIG. 4 with the mandrel moved to bring the packoff closer to the groove in the liner hanger extension tube;

FIG. 6 is the view of FIG. 5 with the dogs latched to the groove and the retaining latch almost released;

FIG. 7 is the view of FIG. 6 showing the retaining latch released.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The FIGS. discussed in detail below belong to a liner hanger assembly shown schematically as anchor slips 10 and seal 12. Their operation is the same as described in U.S. Pat. No. 8,132,619 but the components that have been redesigned to provide the new functionality are the packoff 194 from that patent which is shown in various positions in detail in the FIGS. The new part is referred to by assignee Baker Hughes Incorporated is the RS packoff assembly 6. The initial expansion of the slips 10 is as described in the referenced patent using a running tool featuring an anchor and a stroker that has a swage 14 at its lower end movable relative to mandrel 1 that is secured for run in to nipple 3 through the packoff assembly 6 as shown in the FIG. 1 which represents the run in position with the setting dogs 2 engaged to the groove 3A. The running tool moves relative to the locked in mandrel to initially expand the slips 10. There are gaps between the slips so that if a bottom up cement job is to be performed, the cement is delivered through mandrel 1 through the nipple 3 and the liner 16 through a known cement shoe that is not shown at the lower end of the liner 16 and into the surrounding annulus displacing fluid ahead of it through the gaps between the slips 10 since the seal 12 is at this time still not set. The quality of the cement job can be then tested with known techniques and if it is unsatisfactory due to formation conditions then the present invention enables the performance of a tack and squeeze cement job best seen in the sequence of the FIGS. 1-7. In essence the packoff assembly 6 is released in conjunction with a latch 4 holding the dogs 2 and other components on the packoff 6 from moving relatively to the mandrel 1 also referred to as a slick stinger. Mandrel 1 is raised past the set slips 10 so that the packoff assembly 6 comes into the already expanded portion of the liner hanger and out above. The cement can then be pumped at before for a tack and squeeze job and takes the direction of arrow 18 in FIG. 4 although the lower end 20 is actually moved above slips 10 when the tack and squeeze cementing starts. The cement flows through gaps in the ring of slips 10. There are no returns as it is a squeeze job. When it is over the mandrel 1 is set down following the sequence described below for FIGS. 5-7. Once the re-latching sequence concludes the running tool is again employed to advance swage 14 into the seal 12 to set the seal. The process of FIGS. 1-4 is repeated but this time the mandrel 1 comes out of the hole. The construction of the packoff assembly 6 enables going from a standard cementing job through a shoe in the liner to a tack and squeeze job to augment the original cement job if the original cement job was shown to be inadequate. Both cement jobs can be done in a single trip. The design of the packoff assembly takes away concerns for how much seal friction there is in seals 6B and 22. The dogs 2 are held by latch 4 when released from groove 3A to assure smooth operation when the movements are reversed after the tack and squeeze cement job so that the dogs 2 will not bind when entering the narrowing taper on the way to groove 3A. Flow paths are also provided through the packoff 6 in the form of flats 1D that go under seal 22 after entering at 7A in the retainer ring 7. A no go 24 stops re-entry movement such that the dogs 2 align with groove 3A.

FIG. 1 represents the run in position and the position during setting the slips 10 and while performing a bottom up cement job.

FIG. 2 shows the onset of release of the RS packoff assembly 6 from the RS nipple 3, pick up slick stinger 1. Latch 4 will engage over the latch dogs 9 while the setting dogs 2 are still locked in the groove 3A and over the larger diameter 1B of the slick stinger 1 due to the slotted diameter 1D-FIG. 2A. FIG. 2B shows an isometric view of the slotted diameter. The slotted diameter 1D prevents setting dogs 2 from moving inward since it provides sufficient support and yet allow flow bypass during pick up of the RS packoff 6. In order to enable the latch 4 to slide over the latch dogs 9, a spring 8 is compressed when the latch dogs 9 moves radially inward. The radial movement and force are translated to an axial movement and force by a ramp. The axial force compresses the spring 8.

FIG. 3 shows picking up the slick stinger 1 and setting dogs 2 becoming unsupported, moving radially inward, and not locked in the groove 3A of the RS nipple 3 due to smaller outer diameter 1A of the slick stinger 1. The latch 4 and latch dogs 9 are enabled to move relative to each other. The retrieving collar 5 will no-go on the inner diameter 4A of the latch. Flow bypass is enabled thru the RS packoff assembly 6 which enters from the top thru holes 7A of the retainer ring 7, thru the annulus 6B, then exit thru holes 4B.

FIG. 4 shows continuation of picking up slick stinger 1 and entire RS packoff assembly 6 moves up and away from the groove 3A and RS nipple 3. Entire inner string can be pulled out of the hole or for a specified length depending on the current step of the well completion process. For a tack and squeeze job the stinger 1 is lifted above the set slips 10 as explained above.

FIG. 5 shows the movements after a tack and squeeze job starting with re-sealing the RS-packoff assembly 6 into the run-in position (reference FIG. 1), by moving the slick stinger 1 downward. The force to unlock the latch 4 will be higher than the friction on the outer seals 6C in order to keep the latch 4 locked with the latch dogs (9) which pulls the RS packoff assembly 6 downward together until the retainer ring 7 engages a no-go 24 against the inner diameter 3B of the RS nipple 3. The outer seals 6C are re-sealed in the RS Nipple 3 and the setting dogs 2 are aligned with the groove 3A.

FIG. 6 shows moving slick stinger 1 downward to transfer a radial force on the latch dogs 9 which will transfer an axial force by a ramp to compress a spring 8. Compression of the spring 8 allows the latch dogs 9 to move radially inward and unlock or disengage from the latch 4, allowing slick stinger 1 to continue to move down. Setting dogs 2 are pushed radially outward due to the larger diameter 1B on the slick stinger 1. The setting dogs 2 are locked into the groove 3A.

FIG. 7 shows moving slick stinger 1 down, so that inner seals 22 of the RS packoff assembly 6 are re-sealed on the full outer diameter 1C of the slick stinger 1 and the latch 4 is completely unlocked or disengaged from the latch dogs 9.

Several noteworthy features of the present invention need to be emphasized. First is that a liner hanger can permit a standard cement job as well as a tack and squeeze cement job in either order but preferably the standard cement job first without a trip out of the hole. This can be accomplished with any liner hanger whether it sets with expansion as in the preferred embodiment or whether it sets with pressure on dropped balls or some other way. The features of the packoff 6 that enable the two procedures to be done in a single trip followed by setting the seal 12 are that the dogs 2 get retained to the slick stinger 1 when unlocked and then in the process of re-latching the dogs 2 latch 4 is released to allow the stringer to further advance and lock in the dogs 2 and to enable the inner seal 22 as it travels past the flats shown in FIG. 2B to reseal to the slick stinger 1. When the dogs release by upward slick stinger movement the seal 22 goes over the flats 1D to open up a flow passage to allow the packoff 6 to move up without getting liquid locked. As the dogs 2 release their grip the latch 4 engages the latch dogs 9 so that the dogs 2 and slick stinger 1 move up on tandem as flow goes through passage 7A.

The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below: 

We claim:
 1. A completion method for a liner in a surrounding existing tubular, comprising: running in a liner with a liner hanger supported by a running tool; setting at least one slip in said liner hanger against the existing tubular; performing cement jobs in different directions in an annular space surrounding said liner in a single trip into a subterranean location; setting a seal on said liner hanger; removing said running tool from the subterranean location.
 2. The method of claim 1, comprising: releasing said running tool from said liner hanger before cementing said annulus in a top down direction through at least one gap adjacent said slip.
 3. The method of claim 2, comprising: reconnecting said running tool to said liner hanger after said releasing.
 4. The method of claim 3, comprising: setting said seal on said liner hanger after said reconnecting.
 5. The method of claim 3, comprising: providing a packoff assembly connected to said running tool to selectively engage said liner hanger.
 6. The method of claim 5, comprising: selectively locking dogs mounted to said packoff into a groove in said liner hanger with relative movement of a running tool mandrel having different diameters.
 7. The method of claim 6, comprising: retaining said locking dogs against relative axial movement with respect to said mandrel upon unlocking said dogs from said groove.
 8. The method of claim 7, comprising: releasing said mandrel for relative axial movement with respect to said locking dogs to enable locking said dogs to said groove.
 9. The method of claim 8, comprising: selectively opening a fluid path through said packoff assembly upon unlocking said dogs from said groove.
 10. The method of claim 9, comprising: selectively closing said fluid path through said packoff assembly upon locking said dogs to said groove.
 11. The method of claim 10, comprising: defining said fluid path between said mandrel and an inner seal on said packoff assembly.
 12. The method of claim 11, comprising: providing at least one flat on said mandrel; moving said inner seal past an end of said flat to close said fluid path.
 13. The method of claim 12, comprising: opening said fluid path before unlocking said dogs from said groove.
 14. The method of claim 7, comprising: moving biased latch dogs having a ratchet profile with said mandrel, as said locking dogs remain latched to said groove, into contact with at least one collet finger with a mating ratchet profile connected to said locking dogs.
 15. The method of claim 14, comprising: opening said fluid path with said locking dogs locked to said groove.
 16. The method of claim 15, comprising: undermining said locking dogs to release from said groove after said ratchets on said latch dogs and collet finger have engaged.
 17. The method of claim 16, comprising: releasing said ratchets on said latch dogs and collet finger after said locking dogs are secured to said groove.
 18. The method of claim 1, comprising: performing a bottom up cement job in said annular space followed by a top down tack and squeeze cement job in said annular space. 